PHNOM PENH — As Thailand’s new Prime Minister Anutin Charnvirakul pushes for a public referendum on whether to revoke the 2000 and 2001 Memorandums of Understanding (MoUs) with Cambodia, regional analysts warn that such a move could unravel decades of diplomacy, deepen mistrust between neighbors, and divide ASEAN at a fragile moment for regional unity.

Anutin’s proposal, framed as a bid to “restore sovereignty” along the contentious border, has raised alarm in Phnom Penh and among Southeast Asia observers who fear that nationalism is being weaponized to serve short-term political goals.

Last month, Anutin announced plans to hold a national referendum on scrapping the two agreements, claiming that “the mutual understanding” underlying the MoUs had long vanished and that the border issue “remains unresolved after more than two decades.”

He went as far as to boast that his cabinet could unilaterally cancel the agreements “without consulting security agencies,” a statement that left diplomats and legal experts uneasy.

The 2000 MoU, signed under Prime Minister Chuan Leekpai, established a framework for land boundary surveys and demarcation, while the 2001 MoU, under Thaksin Shinawatra, aimed to settle overlapping maritime claims in the Gulf of Thailand. Together, they remain the legal foundation for peaceful border negotiations between the two countries.

For Pavin Chachavalpongpun, a professor at Kyoto University’s Centre for Southeast Asian Studies and author of ‘Rama X: The Thai Monarchy under King Vajiralongkorn’, the roots of this latest escalation lie in the surge of nationalist sentiment following the armed clashes along the border in July.

“Anutin’s decision seems to be driven by pressure from conservative and nationalist factions who believe these agreements have failed to safeguard Thai sovereignty,” Pavin said. “The move is part symbolic posturing, part genuine political risk. By calling for a referendum, the government projects responsiveness to nationalist demands while cleverly diffusing responsibility for a diplomatically dangerous decision.”

A recent survey by the National Institute of Development Administration (NIDA) found that nearly 60 percent of Thais supported revoking the MoUs, despite 44 percent admitting they did not actually understand the content of the agreements.

In Phnom Penh, regional analysts are watching closely. For Seng Vanly, a geopolitical analyst based in the Cambodian capital, Anutin’s political calculus raises more questions than answers.

“Why now?” Vanly asked. “This appears less about policy and more about politics. By stoking nationalist sentiment, Anutin’s government may be seeking to bolster domestic legitimacy at a time when other challenges at home demand attention.”

He added that while referendums can reflect public sentiment, they are no substitute for legality or the painstaking diplomacy required to resolve border disputes.

“If Thailand unilaterally revokes these MoUs, it risks undermining its international credibility and creating new legal ambiguities in the demarcation process,” Vanly warned. “Such a move would strain relations with Cambodia and derail the existing joint efforts to manage the border peacefully.”

From Japan, Pavin shared a similar view but framed it in the context of international law. He noted that both MoUs are registered with the United Nations, meaning that unilateral withdrawal would likely violate the 1969 Vienna Convention on the Law of Treaties (VCLT).

“The legal consequence would be serious,” Pavin said. “Cambodia could take the matter to the International Court of Justice, inflicting long-term damage on Thailand’s diplomatic reputation. Revoking these MoUs would also dismantle the Joint Boundary Commission — the key bilateral mechanism for negotiation — and risk reigniting armed conflict over undemarcated territory and maritime zones.”

Back in Phnom Penh, Him Raksmey, Executive Director of the Cambodian Center for Regional Studies (CCRS), stressed that while Thailand has every sovereign right to pursue its national interests and determine its foreign policy direction, doing so unilaterally would breach the spirit of cooperation embedded in ASEAN and international law.

“Thailand, as a sovereign state, can naturally hold views on any bilateral agreement,” Raksmey said. “However, since the 2000 and 2001 MoUs were jointly signed, the only legitimate way to alter or terminate them is through mutual consent between both governments.”

Raksmey cautioned that any unilateral decision by Bangkok would “severely undermine trust and friendship” and “complicate ongoing efforts for peaceful resolution.” Such a move, he warned, would not only prolong the Cambodia-Thailand dispute but also “damage ASEAN’s unity, which is grounded in consensus and non-interference.”

A Test for ASEAN’s Unity and Credibility

As the debate intensifies, analysts are also looking at the broader regional implications. Pavin said that Thailand’s domestic politicking could ripple across ASEAN, threatening the bloc’s cohesion and credibility.

“This dispute strikes at the heart of ASEAN’s core principles, the so-called ‘ASEAN Way’ of non-interference and peaceful dispute settlement,” he said. “It exposes how limited the organization’s mechanisms are when nationalism and domestic politics collide.”

Seng Vanly agreed, warning that injecting nationalism into border negotiations risks weakening regional solidarity at a time when quiet diplomacy and technical cooperation are most needed.

“Thailand’s leaders must weigh short-term political gains against long-term diplomatic costs,” he said. “Resolving border issues requires expertise, patience, and sustained dialogue—not populist shortcuts.”

Echoing that sentiment, Him Raksmey urged both sides to return to the existing framework of cooperation.

“Instead of pursuing a path that isolates Thailand, both governments should continue to work within the framework of the 2000 and 2001 MoUs,” he said. “Progress should be based on mutual interests, good neighborliness, and the principles of international law.”

For Pavin, the greatest danger lies not in the referendum itself but in how little the public understands what is at stake.

“This lack of informed consent could turn a technical issue into a political weapon,” he said. “When decisions are made on emotion rather than fact, the outcome can be catastrophic—not just for Thailand and Cambodia, but for ASEAN’s stability as a whole.”